Polylysine HCl is produced by salt formation of polylysine free base with hydrochloric acid, neutralizing the free amine groups to form the corresponding ammonium chloride salt. This modification substantially improves aqueous solubility and powder stability, reduces hygroscopicity, and provides a defined molecular weight and purity profile amenable to pharmaceutical-grade standards.
The HCl counterion can be displaced under physiological pH conditions, restoring the polycationic character responsible for antimicrobial and cell-adhesion properties. In food applications, the HCl salt form allows precise dosing and easier dissolution in aqueous systems compared to the free base. It is manufactured under cGMP conditions and subject to the same regulatory framework as poly-L-lysine in the respective application jurisdiction.